Improvement in dentists  mallets



UNITED STATES PATENT OFFICE.

J. N. SCBANTON, OF BENNINGTON, VERMONT, AND H. H. PARSONS, OF HOO- SICKFALLS, NEW YORK.

Specification forming part of Letters Patent N0. 50,633, dated October24, 1865.

To all whom it may concern.o

Be it know that we, J. N. SGRANTON, ofBennington, Bennington county,Vermont, and H. H. PARSONS, ofHoosick Falls,Bensselaer county, New York,have invented a new and Improved Dentists Mallet; and we do herebydeclare that the following is afull, clear, and exact descriptionthereof, which will enable others skilled in the art to make and use thesame, reference being had to the accompanying drawings, forming part ofthis specification, in which- Figure l represents a side elevation ofthis invention. Fig. 2 is a sectional side view of the same, showing theopposite side from that represented by Fig. l. Fig. 3 is a detachedsectional view of the device for releasing the hammer.

Similarletters of referenceindicatelike parts.

This invention consists in a mallet for the use of dentists, and forsuch other purposes as the invention is applicable to, the blow ot'which is produced by the action of' a spring, the hammer being madeinthe form ofa rod of cylindrical or other suitable form, which is guidediu a suitable case and subjected to the action ot' a spring. The innerend of said rod or hammer is opposite to the inner end of another rod,which forms the socket intended to receive the tool, said two rods beingconnected by a springdog. When the tool is pressed on a tooth or on thematerial to be used in filling a tooth, the hammer is forced backagainst the action of its spring, and at a certain point the springydogis released and the hammer is allowed to come down with some force uponthe tool-holder, thereby producing the action of 'a mallet. The forcewith which the hammer comes down depends upon the tension of the springwhich acts on it, and said tension is adjustable so that the force ofthe blow can be regulated. The spring-dog is released by an inclinedplane which raises the same above the end of the rod that connects itwith the hammer.

A represents a case made in the form of a cylinder, or in any othersuitable form or shape, of sheet brass or any suitable material. Thiscase forms the guide for the hammer B, which is inserted in one endthereof, and for the tool holder or socket C, which is inserted in itsopposite end. The inner ends ofthe hammer and ot' the tool-holder areclose together, and the hammer is raised by a spring-catch, a, which issecured kto the tool-handle and the point of which bears against the endof a rod, b, that is guided in suitable loops, o, on the outside ot' thecase and connects by means ot' cords d e` with the hammer. The cord dextends from a plug over a friction-roller, g, secured to the end of therod b, and round a pulley, h, which is attached to the outside of adrum, z', and one end of-this cord is fast to the plugf, while its otherend is fast to the pulley h. rlhe cord e is wound around the drum t' andits ends are tied to studs jj', which project from the hammer, as shownin Fig. l of the drawings. When the hammer is down, the studj bears 011the edge of the case A and the stud j', which projects through a slot inthe case, bears against the end ot' the slot. The drum t' incloses aspring, 7c, the tension of which can be increased or decreased byturning the handle l on the outside of said drum, and which is soarranged that it has a tendency to hold the hammer down in the positionshown in the drawings. When the tool-holder is pressed down upon a toothor other resisting object the hammer is forced up against the action ofthe spring le, and by the proportion between the diameter ot the drumand that of the pulley the motion of the hammer is quicker than that ofthe tool-holder, so that the inner end of the former moves away fromthat of the latter. This upward motion ofthe hammer continues untilthe'point of the spring-catch a, by sliding up the Ainclined plane m, isdisengaged from the end of the rod b, and the hammer is allowed tofollow the action of the spring and to come down upon the toolholderwith a force which depends upon the tension ot' the spring. Byincreasing this tension the force ot' the blow is increased, and viceversa. The force of the blow depends also in some measure upon the timewhen the springcatch releases the rod b, and this time is regulated byshifting the inclined plane m up or down, said plane being secured in astrap, n, which surrounds the case A and can be moved up or down on thesame at pleasure.

When the operator desires to cause the instrument to strike a lighterblow he can do so to a certain extent Without changing the tension ofthe spring 7c. This he does by holding down toward the point of the toolthe inclined plane m with his linger, and thereby disengage sooner thespring-catch and hammer. As soon as the finger is withdrawn the inclinedplane m will be pushed upward on the case to its limit by the action ofthe spring-catch, and the instrument Will resume blows of the sameWeight as before.

Should the operator desire to vary the weight of the blow beyond thelimits attained by moving the inclined plane, it is ei'eeted by changingthe tension of the spring la, as before described.

It is obvious that the connection between the hammer and the spring canbe effected in a great many different Ways, and We do not W'ish toconfine ourselves to the precise mechanism shown in the drawings.

By the use ot' this instrumenta dentist is enabled to produce blows ofthe requisite force with one hand, and he can use his other hand inholding open the mouth of the patient or in performing such worl; forwhich, with a mallet ot' the ordinary construction, he has to dependupon an assistant.

With our mallet the operation of iilling a tooth and other similaroperation can be performed expeditiously, and Without the aid of anassistant.

Having thus described our invention, We claim as new and desire tosecure by Letters Patent- 1 l. The combination of the tool-holder,hammer, spring-catch, and spring, substantially as herein described, sothat by pressing the tool or tool-holder G against a resisting` object,the hammer is forced back against the action of the spring, and thenallowed to come down upon the tool-holder and to produce a blow of moreor less force.

2. Making the tension ot' the spring k adjustable, substantially asherein described, so that the force of the blows of the hammer can beregulated.

3. Theinclined planeamin combination with the spring-catch, tool`holder,and hammer, applied and operating substantially as and for the purposeset forth.

4. Making the inclined plane adjustable on the case A, substantially asand for the purpose described.

J. N. SGRANTON. H. H. PARSONS. W'itnesses A. C. EDDY, I. RUSSELLPARSONS.

